Added disk caching to XML

Added user configurable disk caching to lookups

.gitignore

@@ -33,3 +33,9 @@ nosetests.xml
 .mr.developer.cfg
 .project
 .pydevproject
+
+# Local Settings File
+settings.cfg
+
+# Local XML Cache
+/qrz-xml

qrz/qrz_query.py

@@ -1,8 +1,10 @@
 #!/usr/bin/env python
 #coding:utf-8
 
+import os
 import requests
 import re
+import time
 import xmltodict
 from ConfigParser import SafeConfigParser
 
@@ -54,15 +56,35 @@ def _get_session(self):
 
 
     def callsign(self, callsign):
-        if self._session_key is None:
-            self._get_session()
-        url = """http://xmldata.qrz.com/xml/current/?s={0}&callsign={1}""".format(self._session_key, callsign)
-        r = self._session.get(url)
-        if r.status_code != 200:
-            raise Exception("Error Querying")
-        raw = xmltodict.parse(r.content)
+        raw_xml = ''
+        xml_cache = self._cfg.cache['cache-path']
+        if xml_cache != '':
+            xml_filename = os.path.join(xml_cache, callsign + '.xml')
+            if os.path.isfile(xml_filename):
+                # Cache expires time is file's modification datetime + time allowed for file cache
+                #                                                      secs*mins*hours*days
+                cache_expiry_time = os.path.getmtime(xml_filename) + (60*60*24*int(self._cfg.cache['cache-expires']))
+                if cache_expiry_time > time.time():
+                    raw_xml = "".join(open(xml_filename).readlines())
+                else:
+                    os.remove(xml_filename)                
+        if raw_xml == '':
+            if self._session_key is None:
+                self._get_session()
+            url = """http://xmldata.qrz.com/xml/current/?s={0}&callsign={1}""".format(self._session_key, callsign)
+            r = self._session.get(url)
+            if r.status_code != 200:
+                raise Exception("Error Querying")
+            if xml_cache != '':
+                if not os.path.isdir(xml_cache):
+                    os.mkdir(xml_cache)
+                if r.content.find('<Callsign>') > -1:
+                    open(xml_filename, 'a').writelines(r.content)
+            raw_xml = r.content
+
+        raw_dict = xmltodict.parse(raw_xml)
         calldict = {}
-        if raw['QRZDatabase'].has_key('Callsign'):
-            for key in raw['QRZDatabase']['Callsign'].keys():
-                calldict[key] = raw['QRZDatabase']['Callsign'][key]
-        return calldict
+        if raw_dict['QRZDatabase'].has_key('Callsign'):
+            for key in raw_dict['QRZDatabase']['Callsign'].keys():
+                calldict[key] = raw_dict['QRZDatabase']['Callsign'][key]
+        return calldict

qrz_example.py

@@ -5,4 +5,8 @@
     result = qrz.callsign("w7atc")
     print result['fname'], result['name']
     print result['addr2'], result['state']
-    print result['country']
+    print result['country']
+    # Show all the data available from QRZ.com
+    print '-' * 50
+    for dict_key, dict_value in sorted(result.items()):
+        print u'{0}: {1}'.format(dict_key, dict_value)

settings_example.cfg

@@ -1,3 +1,7 @@
 [qrz]
 username=blah
-password=blahblah
+password=blahblah
+
+[cache]
+cache-path=./qrz-xml
+cache-expires=30 # Days XML allowed to live in cache